A floppy disk which holds a copy of the operating system, or enough of it to start the computer, useful if the computer won't start up properly from the hard disk. Because modern operating systems are so large, these days it is often a boot CD rather than a floppy.

A CD pr DVD which holds a copy of the operating system, or enough of it to start the computer, useful if the computer won't start up properly from the hard disk.

  CD-ROM or Floppy disk used to start a PC or server when it cannot do so from the hard drive. Boot disks are often used when there is a problem with a Hard Drive, but, equally, may be used as a Key Disk security feature when a PC has been deliberately configured by technical staff to refuse to run without the Key Disk present. *** The Information [..]

A boot disk is a removable data storage medium used to load and boot an operating system or utility program. Typically, a boot disc is a read-only medium that stores temporary files on a CD-ROM or flo [..]